LXR linux/fs/btrfs/raid56.h

   1/*
   2 * Copyright (C) 2012 Fusion-io  All rights reserved.
   3 * Copyright (C) 2012 Intel Corp. All rights reserved.
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public
   7 * License v2 as published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 * General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public
  15 * License along with this program; if not, write to the
  16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17 * Boston, MA 021110-1307, USA.
  18 */
  19
  20#ifndef __BTRFS_RAID56__
  21#define __BTRFS_RAID56__
  22static inline int nr_parity_stripes(struct map_lookup *map)
  23{
  24        if (map->type & BTRFS_BLOCK_GROUP_RAID5)
  25                return 1;
  26        else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
  27                return 2;
  28        else
  29                return 0;
  30}
  31
  32static inline int nr_data_stripes(struct map_lookup *map)
  33{
  34        return map->num_stripes - nr_parity_stripes(map);
  35}
  36#define RAID5_P_STRIPE ((u64)-2)
  37#define RAID6_Q_STRIPE ((u64)-1)
  38
  39#define is_parity_stripe(x) (((x) == RAID5_P_STRIPE) ||         \
  40                             ((x) == RAID6_Q_STRIPE))
  41
  42struct btrfs_raid_bio;
  43struct btrfs_device;
  44
  45int raid56_parity_recover(struct btrfs_root *root, struct bio *bio,
  46                          struct btrfs_bio *bbio, u64 stripe_len,
  47                          int mirror_num, int generic_io);
  48int raid56_parity_write(struct btrfs_root *root, struct bio *bio,
  49                               struct btrfs_bio *bbio, u64 stripe_len);
  50
  51void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,
  52                            u64 logical);
  53
  54struct btrfs_raid_bio *
  55raid56_parity_alloc_scrub_rbio(struct btrfs_root *root, struct bio *bio,
  56                               struct btrfs_bio *bbio, u64 stripe_len,
  57                               struct btrfs_device *scrub_dev,
  58                               unsigned long *dbitmap, int stripe_nsectors);
  59void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio);
  60
  61struct btrfs_raid_bio *
  62raid56_alloc_missing_rbio(struct btrfs_root *root, struct bio *bio,
  63                          struct btrfs_bio *bbio, u64 length);
  64void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio);
  65
  66int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info);
  67void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info);
  68#endif
  69